Ok I can solve problems a,b and g.

a) P { no two alike } = = 0.0926

b) P { one pair } = = 0.4630

g) P { five alike } = = 0.0008

However the trick I used for b doesn't work for c,d,e and f, and I don't understand

why? This is how I solve b:

The numerical value for the pair can be chosen in 6 ways and can be placed in ways, and then there are 3 'slots' left. The numerical value for the remaining 3 slots can be chosen in 5*4*3 ways. The whole thing is divided by the total number of possibilities which is .

But as I said this same line of reasoning doesn't work for c,d,e and f? Am I doing something wrong?